Biomedical subjects

J Byrnes

Publications and source records attributed to J Byrnes.

7 recordsLinked to original sources

PubMed1995

Differential transcription efficiency of two Ig VH promoters in vitro.

Each Ig variable region gene segment is transcribed from its own unique promoter. While all of these promoters share common consensus elements that contribute to the B cell-specific expression of these genes, the DNA sequence of each promoter is distinct. In this study, we have directly compared the transcription efficiencies of two murine heavy chain (VH) promoters in a murine B cell in vitro transcription system. We found that the promoters differed in both transcription efficiency and the ability to bind specific protein complexes. While some of the transcription differences may be attributed to differences in basal promoter elements, the spacing between the octamer and the heptamer consensus elements was found to be important. Others have reported a direct correlation between transcription efficiency and the probability that individual variable region gene segments will rearrange. Our studies may be of direct importance to those interested in identifying B cell-specific transcription factors and may ultimately help to explain differences in the expression of some VH gene segments.

Animals↗

PubMed1995

Integrating outcomes measurement into clinical practice improvement across the continuum of care: a disease-specific episode of care model.

This article describes a model for incorporating outcomes measurement into a comprehensive, continuum-wide clinical practice improvement program developed at Lovelace Health Systems (Albuquerque, N.M.). Created in 1993, the Lovelace Episode of Care Program currently includes nine disease-specific multidisciplinary teams that are working to improve care by addressing such issues as severity, appropriateness, efficiency, continuous quality improvement indicators, practice guidelines, care maps, and outcomes. Key features and advantages of the model are discussed, as well as implementation issues, successes, lessons learned, program restructuring and improvement, and applicability of the framework across diseases and health organizations.

Comprehensive Health Care↗

PubMed1989

Arrangement of repetitive sequences in the genome of herpesvirus Sylvilagus.

Herpesvirus sylvilagus is a lymphotropic (type gamma) herpesvirus of cottontail rabbits (Sylvilagus floridanus). Analysis of virion DNA of herpesvirus sylvilagus has revealed that the genome consists of one stretch of about 120 kilobase pairs of internal, unique DNA flanked by a variable number of 553-base-pair tandem repeats. The G + C content of the repetitive DNA is extremely high (83%), as determined by sequencing. The organization of the herpesvirus sylvilagus genome is, therefore, similar to that of the primate lymphotropic viruses herpesvirus saimiri and herpesvirus ateles.

Base Sequence↗

PubMed1988

Dialysis in the management of pregnant patients with renal insufficiency.

Successful pregnancy in patients on dialysis is uncommon because of a high rate of infertility and complications. The use of hemodialysis to manage pregnant patients needing dialysis has been well reported. However, to our knowledge, only 2 previous cases of pregnant patients using chronic ambulatory peritoneal dialysis (CAPD) have been reported. We discuss 14 pregnancies in 13 women in whom dialysis was used in the management of their pregnancies. Ten pregnancies were successful. Included are 5 successful pregnancies out of 8 managed with CAPD or chronic cycling peritoneal dialysis (CCPD). In comparing the cases managed with CAPD to those managed with hemodialysis, CAPD seems to offer several advantages. These include a more constant biochemical and extracellular environment for the fetus, higher hematocrit levels, infrequent episodes of hypotension, and no heparin requirement. In addition, intraperitoneal insulin facilitates the management of blood glucose in diabetics, and intraperitoneal magnesium facilitates the management of premature labor. Infection, loss of intraperitoneal volume, and loss of peritoneal clearances for solutes and water were not found to be problems.

Adult↗

PubMed1986

Aortic root abscess. Initial experience using magnetic resonance imaging.

The detection of aortic root abscess by magnetic resonance imaging has not been described previously. We report a patient with an aortic root abscess that was successfully diagnosed by magnetic resonance imaging and echocardiography. Computed tomography failed to detect the abscess. The patient recovered with antibiotic therapy. Based on this case and other reports in the literature, we advocate treating similar patients without surgery. We recommend magnetic resonance imaging as an investigational method where the diagnosis of aortic root abscess is ambiguous.

Abscess↗

PubMed1982

Sinus histiocytosis with massive lymphadenopathy: a case with unusual skin involvement and a therapeutic response to vinblastine-loaded platelets.

A patient with sinus histiocytosis with massive lymphadenopathy had unusual skin lesions and progressive internal involvement. Both aspects responded dramatically to the administration of vinblastine-loaded platelets. Vinblastine-loaded, idiopathic thrombocytopenic purpura antibody-coated platelets are a rationale therapy for a disease characterized by the presence of actively phagocytosing histiocytes.

Antibodies↗

PubMed1980

The effects of short- and long-term exposure of chick embryos to neutral red on the frequency of sister-chromatid exchange.

The chick embryo was used to study the effects of neutral red (NR) on the frequency of sister-chromatid exchange (SCE) in specific tissues exposed to this mutagen for short and long periods as development proceeded. In short-term trials, aqueous NR at doses of 10, 25 and 100 micrograms was injected in 3-day and 6-day embryos. In each case, embryos were also treated with 5-bromodeoxyuridine (BrdU) for a 24-h period (two cell cycles) and harvested at 4 days and 7 days, resp. A long-term exposure (about 8 cell cycles) was achieved by exposing embryos to NR from day 3 to day 7 of incubation. At a NR dose of 25 micrograms, the chronic exposure resulted in a doubling of the rate of SCE (11.4/cell) over that observed in embryos exposed for only 24 h at either days 3-4 (6.0/cell) or days 6-7 (6.0/cell). At 100 micrograms of NR, the same relationship held with SCE rates of 14.2/cell for the chronic exposure versus rates of 8.0/cell (3-4 days) and 6.9/cell (6-7 days). At 10 micrograms of NR, no such accumulation of SCE occurred upon long-term treatment. These results show an enhanced SCE response upon growth of embryonic cells in the presence of NR for several days. This may be the result of the persistence of past lesions with the addition of more lesions upon continued exposure to NR.

Animals↗